Ignition coils as are suitable for use with internal combustion engines act to provide a high voltage level electrical current which may be supplied to a spark plug. The current supplied is at a sufficient potential to create an arc across the spark plug gap to ignite the gasoline in the cylinder to power a piston of the internal combustion engine. In order to create this high voltage power source, a primary coil and a secondary coil are positioned relative to each other such that high voltage is generated in the secondary coil.
A particular type of ignition coil has a plastic housing which defines a high voltage opening in which a cup shaped high voltage terminal is secured. The housing additionally includes a main opening in which the primary and secondary coils are secured and wherein they are encapsulated within an epoxy material to pot the entire structure. With such a structure, however, it is necessary to make an electrical connection between an extending lead from the secondary coil and the high voltage terminal. This solder connection is made within the interior of the housing and is in effect a blind joint.
The previous method of performing this solder joint included melting a bead of solder of significant size and allowing this bead to become affixed to the inwardly extending end of the high voltage terminal and then inserting the terminal into the terminal opening in the housing. The secondary coil was then positioned in the main opening with secondary lead contacting the solder bead. The operator would manually hold the secondary coil in position while a heated rod is inserted into the center of the cup shaped high voltage terminal to make physical contact therewith. The heated rod would act to re-melt the bead of solder on the terminal and by holding the secondary coil in position relative to the melted solder and against any force applied by the heated rod, a solder joint could be formed.
However, in the above described method it is necessary to position the ignition coil in the desired orientation, to insert the heated rod into the high voltage terminal and to simultaneously manipulate the secondary coil to be aligned with the solder bead and to maintain the secondary lead in contact with the solder bead as physical force is applied within the high voltage terminal by the heated rod. Although effective, this method requires several manual steps, a skilled operator and, of necessity, must use a relatively large solder bead.
The hereinafter described method accomplishes soldering using noncontact soldering methods and solder paste. In such a manner, the quantity of soldering material utilized as well as the number of steps necessary to perform the soldering operation are reduced.